Instead, the research found a small but significant benefit to a treatment — which claims to remove heavy metals from the body with medicine administered intravenously — that for 50 years has been criticized by mainstream doctors and touted by “alternative” ones.

The positive result triggered a firestorm of opposition from some cardiologists who dismissed the study as junk science; while others defended the study, published in the prestigious Journal of the American Medical Association, as no more flawed than any other.

The emotional debate reinforces the importance of scientific research, several doctors and ethicists said, even as it shows weaknesses in the scientific process. And it raises questions about the attitudes many doctors have toward alternative medicine.

Mainstream medicine today is based on the idea that evidence is king. When well-done trials show a treatment’s benefits outweigh its risks, doctors are expected to use that treatment; when studies show high risk or ineffectiveness, they’re expected to drop it.

That’s why Harlan Krumholz, a Yale University cardiologist, says he doesn’t feel comfortable ignoring the large, federally funded chelation trial, known as TACT, even though he was stunned by its positive conclusion and wants more evidence before he’d be willing to chelate his patients

“If you’re going to do a study you have to live with the result,” said Krumholz, director of Yale-New Haven Hospital Center for Outcomes Research and Evaluation, who was not involved in the research. “I can’t, because it’s an inconvenient result, dismiss it.”

He said he certainly would have believed the trial if it had found chelation to be dangerous and ineffective.

Chelation uses chemicals to grab metals such as lead, zinc, iron, aluminum, and copper, inside the body and flush them out. The therapy, which is delivered through an intravenous drip, like chemotherapy, is used to treat people – mainly children – with lead poisoning.

No one knows how many people use the chelation drug EDTA to treat heart disease, but rough estimates suggest somewhere around 50,000 per year.

Dr. Steven E. Nissen, chairman of cardiovascular medicine at the Cleveland Clinic, said he thinks all those people should immediately stop a therapy he still considers risky and ineffective.

Nissen said he supports spending taxpayer money to study alternative therapies, like chelation, but only when the studies are done well. This one, in his opinion, wasn’t.

“I see this as $31 million in taxpayer money that did not yield a result that was reliable,” Nissen said. “Doing a poor study is worse than doing no study at all.”

Others, including Krumholz, agreed that the study has flaws, but said every other study does as well. At least this one was conducted by reputable researchers with nothing to gain financially or otherwise from a positive result, Krumholz said.

No one was more surprised by the results in the TACT trial than the researchers who conducted it.

A photo of the meeting where they first learned the results shows shock and dismay, said Gervasio A. Lamas, chief of Columbia University’s division of cardiology at Mt Sinai Medical Center in Miami Beach, Fla.

“We really do look astonished,” Lamas said. “Some people had their head on the table saying: ‘no, you’ve got to be kidding me.’”

Lamas said he felt he had to study chelation after a patient came to him asking whether to use the therapy. His first reaction, he said, was “of course not!” Then he began to research the treatment and realized that the “only correct answer was: I don’t know.”

That’s why he launched the nearly decade-long TACT trial, treating more than 1,700 patients with either chelation or a placebo. His team included highly reputable cardiologists as well as experts in statistics and in running clinical trials.

The patients who took EDTA chelation versus a placebo were “modestly” less likely to have a subsequent heart attack, stroke or need a stent, the trial found.

Doctors and patients should not see the trial as a reason to start chelation, said Dr. Howard Bauchner, editor in chief of JAMA, which published the study in its March 27 issue.

Bauchner said he and other JAMA editors debated whether to publish the study at all, because it was so controversial. In the end, they opted to publish it because taxpayers funded the research, which was conducted by well-reputed scientists; because patients are already using chelation regardless of what scientists think; and because JAMA, unlike some other publications, has the editorial resources to fully vet the study and to place it in context, Bauchner said.

The results need to be repeated in other studies, he said – as is standard for all treatments. And someone needs to explain how and why this chemical brew might help open arteries throughout the body, reducing risk of heart disease.

What made the TACT trial so hard for some to stomach, Bauchner said, “is people didn’t believe there was a very good biological basis to the treatment.”

Now, lab research is needed to explain why chelation might reduce the risk of a second or third heart attack, and to study whether it actually reduces death too, Bauchner said.

Dr. Guy Pugh, medical director of the Marino Center for Integrative Health in Cambridge, who participated in the trial, said the study makes him more comfortable with the chelation his center offers. For the last 15 years, his center has quietly treated heart disease patients who came looking for chelation therapy. At least now, he said, he knows the treatment isn’t doing them any harm.

He said a handful of patients a year come to the center looking to continue chelation started elsewhere. “I always explain it’s unproven, we think it’s safe but don’t know its effectiveness or mechanism of action.”

At least half of them give up, he said, when they realize how much effort chelation takes. Patients get a three-hour IV infusion of the chemicals every week for about six months, and have to swallow giant vitamin pills every day during that time.

“Most people don’t have that kind of time,” Pugh said.

Doctors and patients need to be careful about lumping all alternative therapies into one category, said Dr. Josephine Briggs, director of the National Center for Complementary and Alternative Medicine, an arm of the National Institutes of Health.

Some federally funded research has shown that acupuncture and meditation do meet the standards of science and are sometimes more effective than mainstream medicine. Other studies have shown that products like echinacea and St. John’s wort don’t have the benefits that some hoped they would, so customers who buy them may be wasting their money.

Briggs said her agency, known as NCCAM, has tried to answer important medical questions and check the safety of practices that patients are doing anyway.

“There are so many complementary and alternative practices out there, we can’t take on the whole waterfront,” she said. “We’re not in the business of debunking the magnets people put on their knees. We’re focusing on things that look important and plausible or areas of real medical concern.”

What works and what doesn’t

Alternative treatments supported by clinical research:

Acupuncture for pain (but not for polycystic ovary syndrome)

Mindfulness meditation for stress and pain

Clinical hypnosis for postmenopausal hot flashes

Omega-3 fatty acids from fish oil for anxiety in healthy young adults

Alternative treatments that failed to meet the standards of science:

Echinacea for upper respiratory problems

St. John’s wort for depression

Ginkgo for mental decline, memory, or lowering blood pressure

Ephedra for long-term weight loss (research also suggests a high side-effect risk)

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